Sorry I didn't notice this thread since it I thought it was about normal git auth and not ESOUI related. (moved to our site forum)
Looking at our logs I have some issues with some ssh-ed25519 keys that I'm debugging and grepping your IP in my logs you are hitting that issue.
Try an RSA key, I know you said you tried one already but maybe generate a RSA key
Code:
ssh-keygen -t rsa -b 4096 -f key-for-esoui
Make sure git is using that key when talking to our git server. If you have both default id_* private keys in .ssh it will try and use the ed25519 key by default. So you could add to your .ssh/config something like this...
Code:
host git.esoui.com
user git
HostName git.esoui.com
port 22
IdentityFile ~/.ssh/key-for-esoui
Then grab the public end
Code:
cat ~/.ssh/key-for-esoui.pub
and add it to your keys here.